Classifications

• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B7/00—Hydraulic cements
  • C04B7/345—Hydraulic cements not provided for in one of the groups C04B7/02 - C04B7/34
  • C04B7/3453—Belite cements, e.g. self-disintegrating cements based on dicalciumsilicate
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
  • C04B2111/00034—Physico-chemical characteristics of the mixtures
  • C04B2111/00215—Mortar or concrete mixtures defined by their oxide composition
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P40/00—Technologies relating to the processing of minerals
  • Y02P40/10—Production of cement, e.g. improving or optimising the production methods; Cement grinding
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P40/00—Technologies relating to the processing of minerals
  • Y02P40/10—Production of cement, e.g. improving or optimising the production methods; Cement grinding
  • Y02P40/121—Energy efficiency measures, e.g. improving or optimising the production methods

Definitions

• the present invention relates to building materials, in particular a method for producing a binder for concrete, mortar or plaster and a binder prepared according to this method and its use.
• the hydraulic reactivity describes the reaction of a binder with water to form a solid material. In contrast to Alit, Belit hydration slowly occurs over several months and years.
• a-C2SH converts to various C 2 S modifications, which on further heating to 920-960 ° C in the a'L phase and on cooling ß-C 2 S form.
• a disadvantage of this is the high proportion of inert YC 2 S.
• DE 10 2009 018 632 discloses a process for the preparation of a lime-containing binder in which an intermediate which is between 120 ° -250 ° C. by hydrothermal treatment of the starting material with a molar ratio Ca / (Si + Al) between 1, 5 and 2.5 was prepared, a reaction grinding at 1 00-200 ° C between 5 min and 30 min is subjected.
• the disadvantage is that the
• Reaction milling is an energetically inefficient step. Furthermore, sufficient compressive strength after hardening can only be achieved by adding flow agents.
• DE 10 2005 037 771 discloses a process for the production of belite cement, in the ⁇ -dicalcium-silicate hydrate (aC 2 SH) at 100-300 ° C by a hydrothermal treatment of the starting material, the CaO and Si0 2 in the molar Ca / Si ratio contains 1, 5-2.5 arises.
• aC 2 SH is converted into hydraulically reactive C 2 S modifications (belite cement).
• the disadvantage of this is that the combustion process at a relatively high temperature (above 500 ° C) must be performed.
• the problem is solved by a method for producing a
• Binder comprising the steps:
• step b) hydrothermal treatment of the starting material mixture prepared in step b) in an autoclave at a temperature of 100 to 300 ° C and a residence time of 0.1 to 24 h, wherein the water / solid ratio of 0.1 to 100,
• step d) annealing the intermediate obtained in step c) at 350 to 495 ° C, wherein the heating rate of 10 - 6000 ° C / min and the residence time of 0.01 - 600 min,
• the molar ratio of calcium to silicon of 1, 5 to 2.5, preferably about 2, be. In determining this ratio, those compounds are considered that are inert in the manufacturing process.
• quartzes, sands or gravels are used as raw materials for the starting material.
• raw materials which, besides S1O2, also contain CaO, so that the desired Ca / Si ratio is already present. If the desired Ca / Si ratio is not present, then the materials must be prior to further treatment with respect to the chemical composition by adding further reactants such as Ca or Si-containing solids to adjust the required Ca: Si ratio of 1, 5 to 2 , 5 are set.
• Portlandite Ca (OH) 2 or burnt or unfired lime are suitable for this purpose, for example.
• the raw materials are also in terms of grain size and particle size distribution by mechanical or
• thermal treatment can also lead to an optimization of the chemical composition.
• fine grain material is selected as the starting material, whose largest grain is preferably at most 0.1 mm.
• the finer grain fractions from the reprocessing of cementitious binders in building materials such as used concrete and cement are used.
• a finer starting material is advantageous both in terms of the reaction rate, as well as in terms of the cost of grinding the finished cement. With a correspondingly fine starting material, grinding can be dispensed with.
• additional elements or oxides in an amount of 0.1 to 30 wt .-% is required.
• Sodium, potassium, boron, sulfur, phosphorus or combinations thereof are preferred as these additional elements / oxides, also collectively referred to as impurity oxides.
• alkali and / or alkaline earth metal salts and / or hydroxides are suitable, for example CaSO 4 H 2 O, CaSO 4 - 1/2 H 2 O, CaSO 4, CaHPO 2 -2H 2 O, Ca 3 P 2 O 8, NaOH, KOH, Na 2 CO 3 , NaHCO 3 , K 2 CO 3 , MgCO 3 , MgSO 4 , Na 2 Al 2 O 4 , Na 3 PO 4 , K 3 PO 4 , Na 2 [B 4 O 5 (OH) 4 ] -8H 2 O, etc.
• the starting material mixture has a P / Si molar ratio of about 0.05 and / or S / Si of about 0.05 and / or Ca / K of about 0.05.
• raw material mixture may optionally with crystallization seeds containing calcium silicate hydrates, added, so be vaccinated.
• the reaction can be accelerated by seeding with compounds containing from 0.01 to 30% by weight of various calcium silicate hydrate, in particular with ⁇ -2CaO.sub.SiO 2 H 2 O, afwillite, calciochondrodite, ⁇ -Ca 2 SiO 4 and other compounds.
• step c) The prepared mixture of raw materials, which may be inoculated as described above, is then subjected in step c) a hydrothermal treatment in an autoclave at a temperature of 00 to 300 ° C, preferably from 150 ° C to 250 ° C.
• a hydrothermal treatment in an autoclave at a temperature of 00 to 300 ° C, preferably from 150 ° C to 250 ° C.
• preference is given to a water / solids ratio of from 0.1 to 100, preferably from 2 to 20, and residence times of from 0.1 to 24 hours, preferably from 1 to 16 hours.
• the mixture of raw materials can be fired in an additional step. This step is particularly preferred when using industrial By-products or relatively less reactive or coarse materials as raw materials. Temperatures of 400 to 1400 ° C, preferably from 750 to 1100 ° C, are suitable. The burning time is 0.1-6 hours, preferably 1 hour. The burning of the raw materials has the advantage that substances which are otherwise hardly / can not be used in a targeted manner (eg crystalline ashes and slags, etc.) are made possible by improved / greater reactivity in the autoclave to the intermediate product aC ⁇ SH ( by deacidification and or drainage ).
• targeted precursor phases eg reaction-resistant barks
• products after step c) and d) with particularly high contents of X-C2S, aC 2 S and / or at least one reactive, X-ray amorphous Phase have.
• belite as a raw material for the autoclave process is an improved phase composition of the final binder over unfired raw materials.
• step c) The product produced by mixing and, if necessary, burning the raw materials is converted according to step c) in the at least one calcium silicate hydrate and optionally further compounds containing intermediate product by hydrothermal treatment. This is done in an autoclave, at a temperature of 100 to 300 ° C and a residence time of 0.1 to 24 h, wherein the water / solid ratio of 0.1 to 100.
• the intermediate thus prepared is annealed at a temperature of 350 ° C to 495 ° C.
• the heating rate of 10 - 6000 ° C / min, preferably from 20 - 100 ° C / min and more preferably about 40 ° C / min, and the residence time of 0.01 - 600 min, preferably from 1 - 120 min and more preferably from 5 to 60 minutes.
• the binder according to the invention contains 30-100% of the following compounds: x-Ca 2 Si0 4 , X-ray amorphous compounds of variable composition, ⁇ -Ca 2 Si0 and reactive y-Ca 2 Si0 4 with a phase-specific Hydration level of mostly at least 50% in the first 7 days after mixing with water.
• the BET surface area of the binder should be from 1 to 30 m 2 / g.
• the Si0 2 tetrahedra in the binder have an average degree of condensation of less than 1.0.
• the water content in the binder is less than 3.0 wt .-%.
• This binder is optionally ground in a conventional manner to a desired fineness or particle size distribution. Milling can be dispensable with fine raw materials and suitable particle size distribution.
• the binder preferably contains x-Ca 2 Si0 4 in a content of> 30 wt .-% and at least one X-ray amorphous phase with a content> 5 wt .-%, with all the proportions of the binder add up to 100%.
• hydraulically highly reactive binder based on Ca 2 Si0 4 can be produced. These are characterized by the fact that very reactive polymorphs and X-ray amorphous phases are contained and the binders have a high specific surface area. Furthermore, the binder also contains v-Ca 2 Si0 4 . The formation of this polymorph is avoided in portland cement production by rapid clinker cooling, since this polymorph makes no contribution to the development of strength. Surprisingly, it was found that, in contrast to the previous production process, this phase, produced by the process according to the invention at a temperature ⁇ 500 ° C, shows a good reactivity.
• the invention also relates to all combinations of preferred embodiments, insofar as they are not mutually exclusive.
• the information "about” or “approx.” in conjunction with a numerical value mean that at least 10% higher or lower values or 5% higher or lower values and in any case 1% higher or lower values
• a-2CaO Si0 2 H 2 0 was followed by autoclaving at 200 ° C for 16 hours where the mixture was converted to an intermediate. This contained 90 wt .-% a-2CaO Si0 2 H 2 O, 2 wt .-% calcite and 8 wt .-% amorphous constituents.
• the subsequent annealing at 475 ° C converted the intermediate into a reactive binder consisting of 63 wt .-% x-Ca 2 Si0 4 , 15 wt .-% ß-Ca 2 SiO 4 , 7 wt .-% Y-Ca 2 Si0 4) 2 wt .-% calcite and 13 wt .-% X-ray amorphous
• FIG. 1 shows the measured heat rate and heat release.
• a-2CaO Si0 2 H 2 0 was followed by autoclaving at 200 ° C for 16 hours where the mixture was converted to an intermediate. This contained 84 wt .-% a-2CaO Si0 2 H 2 0, 1 wt .-% calcite, 4 wt.% Wollastonite and

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Ceramic Engineering (AREA)
• Materials Engineering (AREA)
• Structural Engineering (AREA)
• Organic Chemistry (AREA)
• Silicates, Zeolites, And Molecular Sieves (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)

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Citations (9)

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• 2012
  • 2012-06-20 EP EP12004620.6A patent/EP2676943B2/de active Active
  • 2012-06-20 ES ES12004620T patent/ES2538091T5/es active Active
  • 2012-06-20 PL PL12004620T patent/PL2676943T5/pl unknown
• 2013
  • 2013-06-10 US US14/409,504 patent/US9321682B2/en active Active
  • 2013-06-10 UA UAA201500433A patent/UA114914C2/uk unknown
  • 2013-06-10 CA CA2875404A patent/CA2875404C/en not_active Expired - Fee Related
  • 2013-06-10 CN CN201380032248.XA patent/CN104540792B/zh not_active Expired - Fee Related
  • 2013-06-10 BR BR112014031245A patent/BR112014031245A2/pt not_active IP Right Cessation
  • 2013-06-10 WO PCT/EP2013/001690 patent/WO2013189573A1/de active Application Filing
  • 2013-06-10 EA EA201590050A patent/EA031022B1/ru not_active IP Right Cessation
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• 2015
  • 2015-07-24 HK HK15107068.5A patent/HK1206328A1/xx unknown

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